<!DOCTYPE html>
<html>

<head>
    <meta charset="utf-8">
    <title>Vue 测试实例 - 菜鸟教程(runoob.com)</title>
    <script src="https://cdn.staticfile.org/vue/2.2.2/vue.min.js"></script>
    <style>
        .active {
            width: 100px;
            height: 100px;
            background: green;
        }
        
        .text-danger {
            background: red;
        }
    </style>
</head>

<body>
    <div id="app">
        <!--  -->
        <div v-bind:class="[activeClass, errorClass]"></div>
    </div>

    <script>
        new Vue({
            el: '#app',
            data: {
                activeClass: 'active',
                errorClass: 'text-danger'
            }
        })
    </script>
</body>

</html>